You will see some jitter in your sine wave. This is normal for this type of synthesis and is due to rounding errors. Look at the "phase wheel" in a typical DDS for greater insight. Skip down 1/3 of the page to the wheel:
https://www.analog.com/library/analogdialogue/archives/38-08/dds.html
https://www.analog.com/library/analogdialogue/archives/38-08/dds.html